Potassium Ionophores

Valinomycin is highly selective for potassium ions over sodium ions within the cell membrane. Valinomycin functions as a potassium transporter and facilitates the movement of potassium ions through lipid membranes. The stability constant, K, for the potassium-valinomycin complex is 106 and for the sodium-valinomycin complex only 10, maintaining the selectivity of valinomycin for the transport of potassium ions rather than sodium ions in biological systems.